DES MOINES, Iowa — Wooing undecided Iowa voters, Hillary Clinton and Bernie Sanders on Monday night each cast themselves as life-long champions for tackling economic inequity but offered differing visions

for addressing the nation's problems.

Sanders reiterated his calls for free tuition at public colleges and universities and implementing a single-payer health care system that would cover all Americans, even though he would raise taxes to pay for it.

"Yes, we will raise taxes," said Sanders, an admission rarely heard in presidential campaigns. "We may raise taxes, but we are going to eliminate private health insurance premiums for individuals and businesses."

Sanders and Clinton spoke separately at a CNN town hall forum, fielding questions predominantly from voters still undecided before the Feb. 1 Iowa caucuses.

Clinton pushed back at suggestions that she's new to the economic issues that have been at the center of Sanders' campaign.

"I think it's fair to say I have a 40-year record in going after inequality," Clinton said. While the questions she faced where less specific on policy, she emphasized that the tough challenges a president faces — an implicit suggestion that Sanders is proposing unrealistic ideas.

Former Maryland Gov. Martin O'Malley has struggled to win support in the race, despite aggressive campaigning in Iowa. He was cheered enthusiastically when he cited climate change as the top issue young people in America should be concerned about.